0.71
OREGON STATE LIBRARY
Documents Section
.7+1
JUN 13 1955
3
/A
UMENT
LECT 00
tEGON
LECTION
Ve9zaite 94,4deft
Insect Pests
FEDERAL COOPERATIVE EXTENSION SERVICE
OREGON STATE COLLEGE
CORVALLIS
Cooperative Extension work in Agriculture and Home Economics, F. E. Price, director.
Oregon State College and the United States Department of Agriculture, cooperating.
Printed and distributed in furtherance of Acts of Congress of May 8 and June 30, 1914.
Extension Bulletin 747
May 1955
saietv
plecautio#a
All insecticides are poisonous to us in some
degree. However, insecticides can be, and are,
used with safety by hundreds of people every
day. The following suggestions will help you.
Avoid spilling concentrated insecticides on
the skin. If there is accidental contact with
these materials, wash off immediately with
soap and water before continuing your work.
Store all insecticides out of reach of children
and irresponsible persons.
Read the label and follow the manufacturer's
recommendations and precautions.
Keep labels intact. If the label is lost, destroy
the material.
Veleta& 9aldeet Insect Pests
H. H. Crowell
Associate Entomologist
R. W. Every
Extension Entomology Specialist
H. E. Morrison
Associate Entomologist
This bulletin has been prepared for as 5% DDT, 1% rotenone, etc., are
the home, or small acreage, vegetable widely used for home gardens because
grower. Commercial growers may ob- they are easy to handle and apply.
tain more detailed information on spe- Some products are sold in dual-pur-
insect pests from County Ex-
pose containers which serve as dust
tension Agents or from Oregon State
applicators.
Insecticides also are available as
liquid concentrates which form a milky
emulsion when diluted with water.
cific
College.
Home gardeners can control most
insect pests by the proper use of insecticides. There are many kinds of
insecticides and ways of preparing or
formulating each kind for use. Most
of the materials useful in the home
garden are available in small packages
at seed or garden-supply stores. Multipurpose insecticide and fungicide combinations are also available. These pro-
ducts will carry the brand names of
national or local manufacturers and the
labels will list the ingredients.
The dilute dust formulations, such
Insecticide
Aldrin
Baits
Chlordane
CPR'
DDT
Dieldrin
Heptachlor
Lindane
Malathion
Methoxychlor
Nicotine sulfate'
Pyrethrum
Rotenone
Sabadilla
These emulsions can be applied easily
with a compressed-air hand sprayer.
Some manufacturers are now marketing garden hose spray guns especially
designed for use with their products.
If this type of equipment is used, the
manufacturer's directions should be
followed.
Wettable powder formulations require constant agitation in the spray
tank and cannot be applied satisfactorily with the type of equipment us-
Amount to mix with
1 gallon water
1 tablespoon of 25% E.C.1
Purchase ready prepared
4 teaspoons of 40% to 45% E.C.
Dust
concentration
1 tablespoon of 25% E.C.
1 tablespoon of 25% E.C.
1 tablespoon of 25% E.C.
1 tablespoon of 20% E.C.
1 to 2 teaspoons of 50% E.C.
1 tablespoon of 25% E.C.
1 teaspoon of 40% solution
1 to 2 teaspoons of E.C.
1 to 2 teaspoons of E.C.
E.C.Emulsifiable (or liquid) concentrate.
3 CPRContains rotenone, pyrethrins, and activator. Use as directed on label.
1
3 Add small amount of laundry soap to improve effectiveness of nicotine sulfate sprays.
21%
5%
§.,
21%
11%
11%
4% or 5%
5%
4%
0.3%
1% to 1%
20%
ually available to the home gardener.
the material with a rotary tiller, or
Insecticides are also available in a
fork and rake, thoroughly. Deep work-
Soil Treatments.")
The preceding table gives the concentrations of dust formulations commonly available, and suggested dilution
rates for the spray materials. The main
thing to remember, however, is to read
the label and follow the recommendations of the manufacturer.
grub, and cabbage maggot control. A
shallower mix (3 to 4 inches) is suf-
Symphylids
spray and have available a trombone,
compressed air, or power sprayer, mix
1 pint of emulsifiable concentrate in
5 to 10 gallons of water for each 1,000
square feet of soil to be treated. This
granular form for use in soil treat- ing of the insecticides (6 to 8 inches)
ments. (See discussion under "Total is important for wireworm, white
ficient for control of the other soil
pests.
To treat 1,000 square feet of garden
space, use
pound of actual insecti-
cide. For example, use 9 pounds of
24% granular formulation. Or if you
prefer to apply the insecticide as a
Symphylids are small, white, centipede-like creatures that live in the soil.
They feed on germinating seeds, roots,
and tubers of nearly all vegetable va- treatment should be effective for at
rieties. They are present in most soils least two years. Starting with the third
and are serious pests of many vege- year, work about one-fifth of the
table and flower gardens.
original dose into the soil each spring.
Aldrin, dieldrin, or heptachlor, at the This should keep the concentration up
rate of 10 pounds of actual insecticide to an effective level for all the pests
per acre (9 pounds of 24% dust or mentioned above. CautionDo not
granular formulation per 1,000 square overdose. Plant injury can result from
feet) have given satisfactory results in excessive amounts of insecticide in
about half of the experimental trials. the soil.
These insecticides were mixed with
the soil as described under "Total Soil
Treatments." As yet, no sure control
measures have been developed.
Total Soil Treatments
You can control wireworms, cucumber beetle larvae, tuber flea beetle
larvae, carrot rust fly larvae, and white
Cutworms
Cutworms are the larvae of large,
dull-colored moths, often attracted to
lights in summer. These worms spend
the winter as partially grown larvae
or as pupae (resting stage) in the soil.
It is the overwintering larvae which
cause damage to newly planted gardens
grubs by treating the garden soil with in the spring. In late spring, the larvae
aldrin, heptachlor, or dieldrin. In ad- transform into moths which lay eggs
dition, plant injury from seed-corn in June and most of the summer. A
maggot, onion maggot, and cabbage new brood of cutworms may then do
(turnip or radish) maggot will be damage to late-planted beets, corn,
and other vegetables in July.
reduced greatly or eliminated.
Cutworm baits, available readyIt is important that the insecticides
mixed
on the market, are effective
soil.
be mixed thoroughly with the
Work the soil to planting tilth before when plant growth is sparse and when
applying the insecticide. Then work in
applied in the evening. The bait
is
most likely to be taken if the ground since one maggot can ruin the edible
is wet, following a rain or irrigation. root. Total soil treatment with aldrin,
If worms are cutting plants at or heptachlor, or dieldrin will usually give
below the ground level, spray or dust
DDT on the area infested and irrigate,
or rake DDT dust into the top layer of
soil. When the cutworms are feeding
on the foliage of crops such as beets,
one application of 5% DDT dust will
handle them. It is important to kill the
satisfactory control, depending on the
soil type, severity of attack, and other
factors. Several other treatments have
been worked out, one of which is described here. Emulsifiable concentrates
of heptachlor or aldrin are diluted
in water and sprayed or dribbled along
worms at this stage, since they will the rows after the plants come up.
later damage the beet itself.
For home gardeners, an emulsion consisting of 1 tablespoon of the liquid
concentrate in 1 gallon of water may
Cabbage Maggots
used. One pint of this dilute emulThis pest of crucifer or cole crops be
sion will treat 20 feet of row per ap-
is the larva of a fly. The eggs are laid
around the bases of plants during most
of the growing season. Insecticides
should be placed where they will come
into immediate contact with the hatching maggots. Since the eggs hatch in
2 or 3 days, it is very important that
the insecticides be applied promptly
plication. A coarse, fan-type spray can
be used to wet an area about 1-1 to 2
inches wide directly along the rows, or
the emulsion can be dribbled along the
rows from a tin can with a large nail
hole punched in the bottom. Three applications are necessary ; the first just
when the seedlings are showing the
at the time indicated in the recom- first
true leaves, and the next two apmendations. Two control measures are
plications
at about 10-day intervals.
involved, depending on the type of
crop.
The "stem" or "leafy" type crop
(cabbage, cauliflower, broccoli, etc.)
does not require perfect control. In the
plant bed, a soil treatment of i
pound per 1,000 square feet of aldrin,
heptachlor, or dieldrin will protect the
small plants satisfactorily. If the seedlings are to be started in exposed flats,
the sterilized soil can be treated with
aldrin, heptachlor, or dieldrin at the
rate of about 1 teaspoon of 2% dust
per square foot of soil 3 inches deep.
Immediately after transplanting the
sets into the garden, dust or ring the
bases of the plants (1 teaspoon per
plant) with any of the above-men-
Onion Maggot
This insect is the larva of a
fly
and a close relative to the cabbage and
seed-corn maggots. It attacks only
onions. The total soil treatment will
control this pest satisfactorily in most
soil types. If experience shows that
something more effective is needed, a
furrow drench, as described below,
may be tried.
Dribble an emulsion (1 tablespoon
liquid heptachlor concentrate to 1 gal-
lon water) down the seed furrow at
the rate of about 1 pint of the emulsion per 20 feet of row. Then close
the furrow and pack firmly. After the
tioned materials or with lindane or seedling onions emerge, two or three
chlordane dusts.
more applications of the emulsion can
Protection of root crucifers (tur- be made along the rows at about 10nips, radishes, etc.) is more difficult, day intervals.
Control of Vegetable Insect Pests
ettatroi
Tadect cued damage
Vegetables Generally
Cutworms: Several species of dingy,
soil-inhabiting worms damage
crops by cutting off seedlings at
soil line; eating holes in edible
roots; feeding on foliage.
Grasshoppers:
Well
known
insects
Standard poison bait effective if vegetation sparse. DDT dust kills
larvae on foliage and on recently watered soil. Worms most active
in spring or early summer. Attack all vegetables. See section on
Cutworms.
General sprays or dusts of aldrin, heptachlor, or chlordane.
which may be very injurious to
vegetables and flowers in late
summer.
'Slugs: Small molluscs common to west-
ern Oregon. Very destructive to
seedling vegetables, flowers, and
root crops, especially in rainy
Metaldehyde-arsenic baits, applied in evening, are standard recommendation. Metaldehyde dust, applied when needed, may be more
effective where slugs are abundant. Repeat control after rainy
periods.
years.
Earwigs: Pests to seedlings, flowers,
and young trees; mostly around
dwellings.
Spread special earwig bait according to directions on package. Apply
bait in evening as earwigs feed at night. General dusting of premises
with DDT or Malathion is also effective.
Symphylids: Small, white, centipedelike animals. Attack root systems
of most garden plants which they
stunt or kill.
No satisfactory control measure developed yet. See section on
Wireworms: Brown, jointed larvae of
click beetles. Kill young plants;
ruin edible roots and tubers.
Soil treatments with aldrin, heptachlor, DDT, dieldrin. Thorough
and deep (6 to 8 inches) mixing of insecticides in soil before plant-
Symphylids.
tures on lower sides of leaves.
Leaves turn yellow and die.
mites are serious in some seasons, usually in late season.
Blister beetles: Large black or gray
beetles which eat foliage of
vegetables and flowers.
DDT, Malathion, methoxychlor sprays or dusts. Serious pests only
Pill bugs, sow bugs, millipedes: Manylegged arthropods which inhabit
moist, shaded areas. May attack
Malathion dust where abundant, or general dusting of DDT in
areas affected. These pests prefer decaying organic matter and
in certain seasons.
are serious in wet seasons or in greenhouses.
seedling plants or fruits in contact with soil.
Seed-corn maggot: White larva of a
fly similar to cabbage maggot.
Attacks most vegetables, mainly
Total soil treatments with aldrin, heptachlor, or dieldrin will suppress
injury. Large seeds (beans, corn) treated with an insecticide plus a
fungicide can be purchased. See section on Total Soil Treatments.
the germinating seeds.
Asparagus
Asparagas beetle: Bluish-black, yellow.
spotted beetle. Adults damage
sprouts by feeding and egg laying. Beetles and gray larvae defoliate ferns.
12-spotted asparagus beetle: Brick-red,
black-spotted beetle. Adults appear later in spring, attack both
sprouts and ferns. Larvae feed on
berries only.
Rotenone, CPR, methoxychlor, DDT dusts are effective on both
adults and larvae. DDT should be used only on the ferns after
cutting season. Control in late season important to reduce numbers
of beetles overwintering as well as to protect ferns.
Control measures followed for regular asparagus beetle will take
care of 12-spotted species.
Control of Vegetable Insect PestsContinued
Tweet afoot dama9e
eget/tot
Beans
Western spotted cucumber beetle: Yellowish-green, black-spotted bee-
tle common to western Oregon.
Adults easily killed with most insecticides recommended for home
gardens (lindane, CPR, methoxychlor, DDT, malathion.) Beetles
migrate in large numbers, so repeated applications may be neces-
Adults attack seedlings and green
sary.
pods.
Black bean aphid: Black plant louse
which forms colonies on leaves
and pods.
Malathion or nicotine sulfate as dusts or sprays when needed.
Nitidulid beetle: Small, black beetles
which infest blossoms of beans
No effective control known. Beetles migrate in large numbers
during late July and early August. Injury affects the yield of beans
only, not the quality.
and flowers. Cause blossom drop.
Temperatures above 70° F. best for nicotine.
Beets (garden)
Western spotted cucumber beetle: Yellowish-green, black-spotted beetle may attack seedlings. Feeds on
Dusts or sprays of DDT, methoxychlor, lindane, rotenone, malathion
or CPR are effective. Apply lightly when needed. Do not apply DDT
to foliage to be eaten for greens.
foliage at all stages of growth.
Broccoli and Brussels SproutsSee Cabbage
Cabbage, Cauliflower, and Other "Stem" Crucifers
Aphids: Gray, mealy plant lice which
suck
sap
from
all
cole
crop
plants. Form large colonies and
Malathion or nicotine sulfate dusts or sprays. Start control measures
early in season and repeat when necessary. Use laundry soap
with nicotine sprays to improve control.
cabbage worm, cabbage looper,
diamond-back moth larvae and
other caterpillars which feed on
the foliage of cole crops.
materials are etrective it applied careTUlly ana as OTTerl as neeueu.
Root maggots: White maggots may
kill or weaken plants by feeding
Heptachlor, chlordane, aldrin, lindane, dieldrin dusted or ringed
on the roots. Egg-laying fly active
during most of season.
Cabbage flea beetle: Small, blue-black,
jumping insects which eat holes
in leaves of all cole crops.
Worms may be active during entire growing season. Do not use
DDT after heads begin to form.
(1/2 teaspoonful per plant) around bases of plants treatment should
be made within 24 hours of setting plants out in field. See section
on Total Soil Treatments.
DDT dust best when plants are young, because of long residual
action of DDT. Rotenone, lindane, CPR, etc. can be used later in
season or when repeated applications can be made.
Carrots
Rust fly: Straw-colored maggots; ruin
the roots for eating.
Aldrin, chlordane, heptachlor or dieldrin as soil treatments. See
Aphids: Yellowish-gray plant lice on
Nicotine sulfate or malathion sprays or dusts when needed. Aphids
hard to see; weaken plants if not controlled.
foliage in certain seasons.
section on Total Soil Treatments.
Cucurbits (Squash, cucumbers, etc.)
Aphids: Dark-colored plant lice form
large colonies on undersides of
leaves and progressively kill
foliage. Often attended by ants.
Nicotine sulfate or malathion sprays or dusts. Direct to undersides
Squash bug: Large, dark insects appear in late spring. Suck juices
from squash plants, etc.kill
Repeated applications of 20% sabadilla dust directed under leaves
and at base of plants. Important to kill overwintered adults before
leaves and whole vines.
of leaves. Do not apply malathion heavily when leaves are wet
injury to leaves may result.
they lay eggs or kill seedling plants. Hand picking effectivebugs
hide under boards placed in field.
Control of Vegetable Insect PestsContinued
%deer awe damage
eoet,tat
Cucurbits (Squash, cucumbers, etc.)Continued
Cucumber
beetles:
Striped
Methoxychlor dust very effective against both species. Apply lightly.
Most other new insecticides may cause plant injury if applied
heavily and when leaves are wet.
beetles
serious foliage feeders in certain
seasons. Spotted cucumber beetle
not a serious pest of cucurbits.
Eggplant
Western potato flea beetle, Western
spotted cucumber beetle: Tiny,
black, jumping beetles eat holes
Dust lightly with any of the regular garden materials such as DDT,
methoxychlor, lindane, rotenone, CPR. Repeat when necessary.
in leaves. Yellowish-green spotted
beetles feed on young plants.
Spider Mites: Tiny, spider-like creatures on under sides of leaves.
Mites may be particularly injurious to eggplant. See 'spider-mites"
under "vegetables generally".
Lettuce
Western spotted cucumber beetle, various worms: Common black-spotted green beetles, semi-looper
Methoxychlor dusts effective for spotted beetles and semi-looper
worms, especially. Rotenone, CPR, and similar dusts or sprays will
help. Young lettuce plants most susceptible to attack by insects.
worms and other leaf-eating insects sometimes attack lettuce.
Onions
Onion maggot: White worm which
kills seedlings and ruins older
onion bulbs. Parent fly lays eggs
tivedatiVNO
Control difficult in some soils. Pour heptachlor emulsion (1 tablespoon
of liquid concentrate per gallon water) along furrow at seedling time
at rate of about 1 pint per 20 feet of row. See sections on Onion
age to turn white or silvery and
wilt. Reduces onion yields ser-
tive. Thrips appear in mid-season; may not be serious -in western
Oregon most seasons.
iously.
Peas
Pea weevil: Egg-laying weevils appear
when first pods are setting.
Grubs feed on inside of the
green peas.
DDT dusts, two or three applications at 2-week intervals as soon as
first pods set. Early application necessary to kill adult weevils
before egg-laying starts. No control possible after eggs are laid.
Pea aphid: Large, green plant lice
which form large colonies in the
DDT effective, but very slow acting. Malathion or nicotine sulfate
sprays or dusts more effective. Thorough applications important.
growing tips of the vines.
Potatoes
Western potato flea beetle: Bronzeblack, jumping beetle which eats
holes in the foliage.
Dust with DDT when needed. If soil insecticides (see Total Soil
Treatments) are used, foliage feeding may be minor.
Tuber flea beetle: Similar to Western
flea beetle, but jet black. Larvae
Aldrin, dieldrin, heptachlor soil treatment at rate of 2 pounds actual
material per acre (see section on Total Soil Treatments on how to
apply and mix).
feed on and seriously damage
tubers.
Colorado potato beetle: Large striped
beetles and reddish grubs both
eat foliage and vines.
Oregon.
Eastern
DDT dust applied when necessary. Spot dusting at intervals early
in season may save having to dust whole potato patch later or
losing plants to beetles.
Control of Vegetable Insect PestsContinued
ea4oe
Tadeet aced damage
Radishes and Other Root Crucifers
Aphids: Same gray-colored plant louse
which infests cabbage and other
"stem" crucifers (cole crops).
Malathion or nicotine sulfate dusts or sprays. Aphids not as important on "root" crops unless greens are to be eaten.
Cabbage flea beetle: Same blue-black
jumping beetle as found on other
DDT dust in early stages of plant growth. Very important to protect
seedling radishes, turnips, etc.
cole crops.
Diamond-back moth: Small larvae of a
moth which eat holes in leaves,
mostly from under sides.
Root
maggots:
White
maggots
or
worms which feed on the roots
and ruin them for food. Parent
is a fly.
DDT or malathion or similar types dust, directed to under sides of
leaves.
Heptachlor or aldrin emulsion drenches along rows. One tablespoonful of concentrate in
gallon water; apply about 1 pint of
emulsion to 20 feet of row; three applications at 10-day intervals
beginning when seedlings are about 1 inch high. See sections on
1
Total Soil Treatments and Cabbage Maggots.
Spinach
Western spotted cucumber beetle:
Spotted beetles eat holes in
leaves. May be serious on the
seedling plants.
DDT and most other insecticidal dusts or sprays effective.
Do not use DDT close to harvestmethoxychlor, rotenone, CPR
can be used when plants are larger than seedlings.
JVVWGI
Corn earworm:
brown,
Large,
black, or
green (also
worms
red)
which get into tips of ears and
II
DDT dust daubed onto silks of each ear with a brushthree to four
applications at 3-day intervals. Start when silks first appear. DDT
sprays in ear zone also effective.
feed on silk and kernels. Serious
in most areas.
Larvae of Western spotted cucumber
beetle:
Long, straw-colored
Soil treatment with heptachlor or aldrin as described in Total Soil
Treatments.
worms in soil which attack corn
seedlings and roots. Stunts plants
or makes stalks fall over.
Tomatoes
beetle: Small,
Dust lightly with DDT or methoxychlor as needed. Important to
black beetles (same as on potatoes) which attack the leaves in
watch plants for flea beetle damage when tomato sets are still small.
Western
potato flea
early summer.
Hornworm: Very large green worms
with diagonal stripes and single
"horn" at back end.
Hand picking of worms (or snipping with scissors) effective in small
plantings. Dust with DDT. Pest only in eastern Oregon.
TurnipsSee Radishes